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2.  Components of Air Pollution and Cognitive Function in Middle-aged and Older Adults in Los Angeles 
Neurotoxicology  2013;40:1-7.
While experiments in animals demonstrate neurotoxic effects of particulate matter (PM) and ozone (O3), epidemiologic evidence is sparse regarding the relationship between different constituencies of air pollution mixtures and cognitive function in adults. We examined cross-sectional associations between various ambient air pollutants [O3, PM2.5 and nitrogen dioxide (NO2)] and six measures of cognitive function and global cognition among healthy, cognitively intact individuals (n=1,496, mean age 60.5 years) residing in the Los Angeles Basin. Air pollution exposures were assigned to each residential address in 2000–06 using a geographic information system that included monitoring data. A neuropsychological battery was used to assess cognitive function; a principal components analysis defined six domain-specific functions and a measure of global cognitive function was created. Regression models estimated effects of air pollutants on cognitive function, adjusting for age, gender, race, education, income, study and mood. Increasing exposure to PM2.5 was associated with lower verbal learning (β = −0.32 per 10 ug/m3 PM2.5, 95% CI = −0.63, 0.00; p = 0.05). Ambient exposure to NO2 >20 ppb tended to be associated with lower logical memory. Compared to the lowest level of exposure to ambient O3, exposure above 49 ppb was associated with lower executive function. Including carotid artery intima-media thickness, a measure of subclinical atherosclerosis, in models as a possible mediator did not attenuate effect estimates. This study provides support for cross-sectional associations between increasing levels of ambient O3, PM2.5 and NO2 and measures of domain-specific cognitive abilities.
PMCID: PMC3946571  PMID: 24148924
air pollution; cognitive dysfunction; dementia; particulate matter; ozone; verbal learning
3.  Vascular risk and Aβ interact to reduce cortical thickness in AD vulnerable brain regions 
Neurology  2014;83(1):40-47.
The objective of this study was to define whether vascular risk factors interact with β-amyloid (Aβ) in producing changes in brain structure that could underlie the increased risk of Alzheimer disease (AD).
Sixty-six cognitively normal and mildly impaired older individuals with a wide range of vascular risk factors were included in this study. The presence of Aβ was assessed using [11C]Pittsburgh compound B–PET imaging, and cortical thickness was measured using 3-tesla MRI. Vascular risk was measured with the Framingham Coronary Risk Profile Index.
Individuals with high levels of vascular risk factors have thinner frontotemporal cortex independent of Aβ. These frontotemporal regions are also affected in individuals with Aβ deposition, but the latter show additional thinning in parietal cortices. Aβ and vascular risk were found to interact in posterior (especially in parietal) brain regions, where Aβ has its greatest effect. In this way, the negative effect of Aβ in posterior regions is increased by the presence of vascular risk.
Aβ and vascular risk interact to enhance cortical thinning in posterior brain regions that are particularly vulnerable to AD. These findings give insight concerning the mechanisms whereby vascular risk increases the likelihood of developing AD and supports the therapeutic intervention of controlling vascular risk for the prevention of AD.
PMCID: PMC4114172  PMID: 24907234
4.  Preservation of Neurons of the Nucleus Basalis in Subcortical Ischemic Vascular Disease 
Archives of neurology  2012;69(7):879-886.
To compare loss of neurons in the nucleus basalis of Meynert (NB) in subcortical ischemic vascular disease (SIVD) to normal controls, Alzheimer’s disease (AD), and cases with mixed AD/SIVD pathology.
Autopsied cases drawn from a longitudinal observational study with SIVD, AD and normal aging.
Pathologically defined SIVD (n = 16), AD (n = 20), mixed pathology (n = 10), and age- and education-matched normal control (n = 17) groups were studied.
Main Outcome measures
NB neuronal cell counts in each group and their correlation with the extent of MRI white matter lesions (WML) and Clinical Dementia Rating (CDR) scores closest to death.
No significant loss of neurons was found in SIVD compared to age-matched controls in contrast to AD and mixed groups, where there was significant neuronal loss. A significant inverse correlation between NB neurons and CDR scores was found in AD, but not in the SIVD and mixed groups. NB cell counts were not correlated with either the extent of white matter lesions or cortical gray matter volume in SIVD or AD groups.
These findings inveigh against primary loss of cholinergic neurons in SIVD, but do not rule out the possibility of secondary cholinergic deficits due to disruptions of cholinergic projections to cerebral cortex.
PMCID: PMC4184885  PMID: 22393167
5.  Retinal Microvascular Abnormalities and Cognitive Function in Latino Adults in Los Angeles 
Ophthalmic epidemiology  2012;19(3):127-136.
Retinal vessels may provide a readily accessible surrogate approach to study vascular disease in brain small vessels. Previous epidemiologic studies of retinal microvascular abnormalities and cognition have not included large numbers of Latinos who have a high prevalence of diabetes and hypertension.
We used data from 809 elderly Latino participants in the Los Angeles Latino Eye Study (LALES) to assess whether retinal vessel caliber and microvascular abnormalities are cross-sectionally associated with lower cognitive function. Cognitive screening was conducted with the Cognitive Abilities Screening Instrument-Short form (CASI-S) and in-depth testing with the Spanish English Neuropsychological Assessment Scales (SENAS). Retinal photographs were used to identify retinopathy signs and measure retinal vessel caliber.
A total of 65.8% had high blood pressure, 34.5% had diabetes; self-reported diagnoses of heart attack, heart failure, angina and stroke were rare. Retinal calibers and any retinopathy were not associated with the CASI-S, total SENAS or any SENAS cognitive factors assessed as continuous variables. The odds of a low CASI-S score were two times higher in subjects with generalized arteriolar narrowing (OR = 2.04, 95% CI = 1.14, 3.66), and one and half times as high in those with both generalized arteriolar narrowing and retinopathy signs (OR = 1.49, 95% CI = 0.47, 4.75) though this result was based on only four cases with both risk factors and confidence limits were wide and included the null.
Retinal microvasculature imaging may provide insights into small blood vessel influences on cognition in Latino populations. Additional studies in diverse populations and prospective settings are needed.
PMCID: PMC3598630  PMID: 22568425
Epidemiology; Cognition; Retina; Latinos; Microvasculature
6.  Physical Activity and Sex Hormone Levels in Estradiol- and Placebo-Treated Postmenopausal Women 
Menopause (New York, N.Y.)  2011;18(10):1079-1086.
Postmenopausal changes in the hormonal milieu in women with or without hormone therapy (HT) are hypothesized to be the pathway for a number of menopause-associated modifications in physiology and disease risk. Physical activity may modify these changes in women’s hormone profiles. The crucial yet complex relationship between physical activity and physiologic and pharmacologic sex hormone levels in postmenopausal women has not been investigated sufficiently.
Using structured recall, physical activity was assessed longitudinally over two years in 194 postmenopausal women (90 randomized to daily 1 mg 17β-estradiol and 104 to placebo) in the Estrogen in the Prevention of Atherosclerosis Trial. Levels of physical activity were correlated to serum sex hormone and serum hormone-binding globulin (SHBG) levels in each treatment group.
In placebo-treated women, total energy expenditure was positively associated with sex hormone-binding globulin (SHBG) (p<0.001) and inversely associated with testosterones (total, bioavailable, free) and androstenedione (p<0.001 for all), as well as with estradiol (p=0.02). In estradiol-treated women, estradiol levels were inversely associated with total energy expenditure (p=0.002) and weekly hours spent in moderate or more vigorous physical activity (p=0.001).
Physical activity is associated with lower serum levels of estradiol in both HT-treated and untreated women. In placebo-treated women only, physical activity is associated with reduced androgen levels and elevated SHBG levels.
PMCID: PMC3183237  PMID: 21646925
Physical activity; sex hormones; estradiol; menopause
Menopause (New York, N.Y.)  2013;20(8):840-844.
To determine whether long-term isoflavone soy protein (ISP) supplementation affects endometrial thickness and rates of endometrial hyperplasia and cancer in postmenopausal women.
In this randomized, double-blind, placebo-controlled trial, 350 postmenopausal women 45–92 years of age were randomized to a total daily dose of 154 mg of ISP or a milk protein matched placebo for a 3-year period. Women with a surgically absent uterus were excluded from the analysis (final study population: n=224). The main outcome measures were the mean change in endometrial thickness on transvaginal ultrasound from baseline until up to 36 months of follow-up; the incidence of endometrial sampling, endometrial hyperplasia and endometrial cancer.
A total of 666 visits among 224 participants were evaluated. Treatment groups did not significantly differ on the mean baseline or on-trial changes in endometrial thickness. Of the 103 placebo-treated participants, 7 (6.8%) underwent an endometrial biopsy; 6 (85.7%) of these biopsies were benign. One woman in the placebo group was diagnosed with complex endometrial hyperplasia with atypia and underwent a hysterectomy. The pathology result from this surgery was Stage IB endometrial cancer. Of the 121 participants in the soy group, 9 (7.4%) underwent an endometrial biopsy. The results were benign in all 9 cases (100%). Although the rate of hyperplasia / malignancy was higher in the placebo group (14.3% versus 0%), the difference was not statistically significant.
Three-year isoflavone soy protein (ISP) supplementation has no effect on endometrial thickness or rates of endometrial hyperplasia and cancer in postmenopausal women.
PMCID: PMC3934100  PMID: 23422867
Isoflavones; menopause; endometrium; randomized controlled trial
8.  Cerebral Atherosclerosis is Associated with Cystic Infarcts and Microinfarcts, but not Alzheimer Pathologic Changes 
Background and Purpose
Some studies have reported associations between intracranial atherosclerosis and Alzheimer disease (AD) pathology. We aimed to correlate severity of cerebral atherosclerosis, arteriolosclerosis, and cerebral amyloid angiopathy (CAA) with neurofibrillary tangles, neuritic plaques, and cerebral infarcts.
This autopsy study (n = 163) was drawn from a longitudinal study of subcortical ischemic vascular disease, AD, and normal aging. Multivariable logistic regression models were used to test associations among the 3 forms of cerebrovascular disease and the presence of ischemic and neurodegenerative brain lesions. Apolipoprotein E genotype was included as a covariate in these multivariable models.
Cerebral atherosclerosis was positively associated with microinfarcts (odds ratio (OR) = 2.3; 95% confidence interval (CI) = 1.2–4.4) and cystic infarcts (OR = 2.0, 95%CI = 1.0–4.2), but not AD pathology. Arteriolosclerosis showed a positive correlation with lacunar infarcts (OR = 2.0, 95%CI = 1.0–4.2), but not AD pathology. CAA was inversely associated with lacunar infarcts (OR = 0.6, 95%CI = 0.41–1.1), but positively associated with Braak & Braak stage (OR = 1.5, 95%CI = 1.1–2.1) and CERAD plaque score (OR = 1.5, 95%CI = 1.1–2.2).
Microinfarcts, which have been correlated with severity of cognitive impairment, were most strongly associated with atherosclerosis. Possible pathogenetic mechanisms include artery-to-artery emboli, especially micro-emboli that may include atheroemboli or platelet-fibrin emboli. Arteriolosclerosis was positively, while CAA was negatively correlated with lacunar infarcts, which might prove helpful in clinical differentiation of arteriolosclerotic from CAA-related vascular brain injury.
PMCID: PMC4049465  PMID: 23887837
Atherosclerosis; Alzheimer; Microinfarct; Infarct
10.  The Timing Hypothesis: A Paradigm Shift in the Primary Prevention of Coronary Heart Disease in Women: Part 1, Comparison of Therapeutic Efficacy 
The long-held belief that outcome data from intervention trials in men are generalizable to women has created the framework in which the primary prevention of coronary heart disease (CHD) in women is viewed. However, over the past decade, data has accumulated to refute such a supposition of generalizability. These lines of evidence concern the sex-specific efficacy of CHD primary prevention therapies and timing of postmenopausal hormone replacement therapy (HRT) initiation according to age and/or time-since-menopause as modifiers of efficacy and risk. Although the standard primary prevention therapies of statins and aspirin reduce CHD in men, neither therapy reduce CHD, and more importantly total mortality in women under primary prevention conditions. On the other hand, HRT significantly reduces both CHD and total mortality in primary prevention when HRT is initiated in women <60 years old and/or <10 years-since-menopause. Herein, the efficacy of the commonly used therapies for the primary prevention of CHD in women, statins, aspirin and postmenopausal HRT is discussed. In part 2 of this series the comparative risks of these therapies are discussed.
PMCID: PMC3660423  PMID: 23414520
hormone therapy in women; statins; timing hypothesis; women and CHD prevention; 31 meta-analyses
11.  Birth Weight and Carotid Artery Intima-Media Thickness 
The Journal of pediatrics  2012;162(5):906-11.e1-2.
To determine the association between birth weight and carotid artery intima-media thickness (CIMT), a measure of atherogenesis, in a population of 11-year-old children.
Study design
CIMT measured by high-resolution ultrasound, and birth registry data were available for 670 children of the Southern California Children’s Health Study. Multivariate regression analyses were performed to investigate the association between birth weight and CIMT, with adjustment for child’s health status and lifestyle, pregnancy information, and parental health.
Mean CIMT was 0.57 mm (SD 0.04). We found a nonlinear association between birth weight and CIMT, with an increase in CIMT of 0.014 mm in the fifth (P value .01) compared with the third birth weight quintile. These associations were robust in subsample analyses in children considered normal-weight by gestational age or in term-born children. No significant association with CIMT was found for the lowest quintile.
Greater birth weight was significantly associated with increased CIMT at age 11 years. No evidence for an impact of lower birth weight was found. The predictive value of childhood CIMT on future cardiovascular outcomes is largely unknown, but strong associations between childhood cardiovascular disease risk factors and adult vascular disease suggest that increased CIMT in childhood may be clinically important.
PMCID: PMC4030536  PMID: 23260106
12.  The Aging Brain and Cognition 
JAMA neurology  2013;70(4):488-495.
β-Amyloid (Aβ) deposition and vascular brain injury (VBI) frequently co-occur and are both associated with cognitive decline in aging. Determining whether a direct relationship exists between them has been challenging. We sought to understand VBI’s influence on cognition and clinical impairment, separate from and in conjunction with pathologic changes associated with Alzheimer disease (AD).
To examine the relationship between neuroimaging measures of VBI and brain Aβ deposition and their associations with cognition.
Design and Setting
A cross-sectional study in a community- and clinic-based sample recruited for elevated vascular disease risk factors.
Clinically normal (mean age, 77.1 years [N=30]), cognitively impaired (mean age, 78.0 years [N=24]), and mildly demented (mean age, 79.8 years [N=7]) participants.
Magnetic resonance imaging, Aβ (Pitts-burgh Compound B–positron emission tomographic [PiB-PET]) imaging, and cognitive testing.
Main Outcome Measures
Magnetic resonance images were rated for the presence and location of infarct (34 infarct-positive participants, 27 infarct-negative participants) and were used to quantify white matter lesion volume. The PiB-PET uptake ratios were used to create a PiB index by averaging uptake across regions vulnerable to early Aβ deposition; PiB positivity (29 PiB-positive participants, 32 PiB-negative participants) was determined from a data-derived threshold. Standardized composite cognitive measures included executive function and verbal and nonverbal memory.
Vascular brain injury and Aβ were independent in both cognitively normal and impaired participants. Infarction, particularly in cortical and subcortical gray matter, was associated with lower cognitive performance in all domains (P<.05 for all comparisons). Pittsburgh Compound B positivity was neither a significant predictor of cognition nor interacted with VBI.
Conclusions and Relevance
In this elderly sample with normal cognition to mild dementia, enriched for vascular disease, VBI was more influential than Aβ in contemporaneous cognitive function and remained predictive after including the possible influence of Aβ. There was no evidence that VBI increases the likelihood of Aβ deposition. This finding highlights the importance of VBI in mild cognitive impairment and suggests that the impact of cerebrovascular disease should be considered with respect to defining the etiology of mild cognitive impairment.
PMCID: PMC3771392  PMID: 23400560
13.  Association of HIV clinical disease progression with profiles of early immune activation: results from a cluster analysis approach 
AIDS (London, England)  2013;27(9):1473-1481.
CD4 and CD8 T-cell activation are independent predictors of AIDS. The complete activation profile of both T-cell subtypes and their predictive value for AIDS risk is largely unknown.
A total of 564 AIDS-free women in the Women's Interagency HIV Study were followed over 6.1 years (median) after T-cell activation assessment. A cluster analysis approach was used to evaluate the concurrent activation patterns of CD4 and CD8 T cells at the beginning of follow-up in relation to AIDS progression.
Percentages of CD4 and CD8 T cells with HLA-DR± and CD38± were assessed by flowcytometry. Eight immunologic variables (four on each CD4+ and CD8+: DR± and CD38±) were assessed to yield a 4-cluster solution on samples obtained before clinical endpoints. Proportional hazards survival regression estimated relative risks for AIDS progression by cluster membership.
Compared with the other three clusters, outstanding activation features of each distinct cluster of women were: Cluster 1: higher CD8+CD38– DR– (average = 41% of total CD8 T-cell pool), CD4+CD38– DR– (average = 53% of total CD4 T-cell pool), and CD8+CD38– DR+ (28%); Cluster 2: higher CD8+CD38+DR– (44%) and CD4+CD38+DR– (58%); Cluster 3: higher CD8+CD38+DR+ (49%) and CD4+ CD38+DR– (48%); Cluster 4: higher CD8+CD38+DR+ (49%), CD4+CD38+DR+ (36%) and CD4+CD38– DR+ (19%). Compared with cluster 1, women in cluster 4 had two-fold increased risk of AIDS progression (Hazard ratio = 2.13; 95% confidence interval = 1.30–3.50) adjusted for CD4 cell count, HIV RNA, and other confounders.
A profile including CD4 and CD8 T-cell activation provided insight into HIV pathogenesis indicating concurrent hyperactivation of CD4 and CD8 T cells is associated with AIDS progression.
PMCID: PMC3949252  PMID: 23945505
AIDS; cluster analysis; immune activation
14.  Underlying genetic structure impacts the association between CYP2B6 polymorphisms and response to efavirenz and nevirapine 
AIDS (London, England)  2012;26(16):2097-2106.
CYP2B6 variation predicts pharmacokinetic characteristics of its substrates. Consideration for underlying genetic structure is critical to protect against spurious associations with the highly polymorphic CYP2B6 gene.
The effect of CYP2B6 variation on response to its substrates, nonnucleoside reverse transcriptase inhibitors (NNRTIs), was explored in the Women's Interagency HIV Study.
Five putative functional polymorphisms were tested for associations with virologic suppression within one year after NNRTI initiation in women naïve to antiretroviral agents (n=91). Principal components (PCs) were generated to control for population substructure. Logistic regression was used to test the joint effect of rs3745274 and rs28399499, which together indicate slow, intermediate, and extensive metabolizers.
Rs3745274 was significantly associated with virologic suppression (OR=3.61, 95% CI 1.16-11.22, p trend=0.03); the remaining polymorphisms tested were not significantly associated with response. Women classified as intermediate and slow metabolizers were 2.90 (95% CI 0.79-12.28) and 13.44 (95% CI 1.66-infinity) times as likely to achieve virologic suppression compared to extensive metabolizers after adjustment for PCs (p trend=0.005). Failure to control for genetic ancestry resulted in substantial confounding of the relationship between the metabolizer phenotype and treatment response.
The CYP2B6 metabolizer phenotype was significantly associated with virologic response to NNRTIs; this relationship would have been masked by simple adjustment for self-reported ethnicity. Given the appreciable genetic heterogeneity that exists within self-reported ethnicity, these results exemplify the importance of characterizing underlying genetic structure in pharmacogenetic studies. Further follow-up of the CYP2B6 metabolizer phenotype is warranted given the potential clinical importance of this finding.
PMCID: PMC3940150  PMID: 22951632
CYP2B6; population substructure; women; NNRTIs; confounding
15.  Subclinical Atherosclerosis is Weakly Associated with Lower Cognitive Function in Healthy Hyperhomocysteinemic Adults without Clinical Cardiovascular Disease 
Atherosclerosis is the most common pathologic process underlying cardiovascular disease (CVD). It is not well known whether subclinical atherosclerosis is an independent risk factor for lower cognitive function among individuals without clinically evident CVD.
We examined cross-sectional associations between subclinical atherosclerosis and cognitive function in a community-based sample of otherwise healthy adults with plasma homocysteine ≥8.5 µmol/L enrolled in the BVAIT study (n=504, mean age 61 years). Carotid artery intima-media thickness (CIMT), coronary (CAC) and abdominal aortic calcium (AAC) were used to measure subclinical atherosclerosis. Cognitive function was assessed with a battery of neuropsychological tests. A principal components analysis was used to extract five uncorrelated cognitive factors from scores on individual tests, and a measure of global cognition was derived. Multivariable linear regression was used to examine the association between subclinical atherosclerosis and cognitive function, adjusting for other correlates of cognition.
Increasing thickness of CIMT was associated with significantly lower scores on the verbal learning factor (β = −0.07 per 0.1 mm increase CIMT [SE(β)=0.03], p=0.01). CAC and AAC were not individually associated with any of the cognitive factors.
This study provides evidence that increasing CIMT is weakly associated with lower verbal learning abilities but not global cognition in a population of otherwise healthy middle-to-older aged adults with elevated plasma homocysteine but without clinically evident CVD. The association between CIMT and poor verbal learning may pertain particularly to men.
PMCID: PMC2661006  PMID: 18836986
cognitive function; atherosclerosis; cardiovascular disease; memory; verbal learning
16.  Mildly Elevated TSH and Cognition in Middle-Aged and Older Adults 
Thyroid  2009;19(2):111-117.
It is accepted that markedly elevated thyroid-stimulating hormone (TSH) levels are associated with impaired cognitive function. However, the findings regarding the association between mildly elevated TSH levels and cognition are equivocal. The objective of this study was to assess the relation between TSH levels in the normal to mildly elevated range (0.3–10.0 mIU/L) and several domains of cognitive function.
A healthy, community-based sample of 489 men and women (40–88 years old, mean = 60.5 years) enrolled in the B-Vitamin Atherosclerosis Intervention Trial were studied. A neuropsychological test battery was used to assess a broad array of cognitive functions. Four uncorrelated neuropsychological factors were extracted by principal component analysis. Using multivariable linear regression, performance on each factor was examined in relation to TSH levels, controlling for age, gender, race-ethnicity, education, homocysteine levels, low-density lipoprotein cholesterol levels, and smoking status.
TSH levels were not associated with any of the four factor scores in the total sample or in younger (age < 60) or older (age ≥ 60) subjects, although there was a trend for older subjects with higher levels of TSH to do more poorly on paragraph recall (p = 0.06). Gender-stratified analyses showed that TSH was positively associated with scores on word list learning for females only (p = 0.003).
In this community-based sample of middle-aged to older individuals, increasing TSH levels were not associated with significantly reduced cognitive performance in any domain. Further exploration of the effects of gender on the association between TSH and cognition is warranted.
PMCID: PMC2715222  PMID: 19191743
17.  Pioglitazone slows progression of atherosclerosis in prediabetes independent of changes in cardiovascular risk factors 
To determine whether changes in standard and novel risk factors during the ACT NOW trial explained the slower rate of CIMT progression with pioglitazone treatment in persons with prediabetes.
Methods and Results
CIMT was measured in 382 participants at the beginning and up to three additional times during follow-up of the ACT NOW trial. During an average follow-up of 2.3 years, the mean unadjusted annual rate of CIMT progression was significantly (P=0.01) lower with pioglitazone treatment (4.76 × 10−3 mm/year, 95% CI, 2.39 × 10−3 – 7.14 × 10−3 mm/year) compared with placebo (9.69 × 10−3 mm/year, 95% CI, 7.24 × 10−3 – 12.15 × 10−3 mm/year). High-density lipoprotein cholesterol, fasting and 2-hour glucose, HbA1c, fasting insulin, Matsuda insulin sensitivity index, adiponectin and plasminogen activator inhibitor-1 levels improved significantly with pioglitazone treatment compared with placebo (P < 0.001). However, the effect of pioglitazone on CIMT progression was not attenuated by multiple methods of adjustment for traditional, metabolic and inflammatory risk factors and concomitant medications, and was independent of changes in risk factors during pioglitazone treatment.
Pioglitazone slowed progression of CIMT, independent of improvement in hyperglycemia, insulin resistance, dyslipidemia and systemic inflammation in prediabetes. These results suggest a possible direct vascular benefit of pioglitazone.
PMCID: PMC3908828  PMID: 23175674
Carotid atherosclerosis progression; Impaired glucose tolerance; Insulin resistance; Inflammation; Pioglitazone
18.  Metabolic Syndrome and Cognitive Function in Healthy Middle-Aged and Older Adults without Diabetes 
Few studies have addressed whether the metabolic syndrome (MetS) and its individual components are associated with cognitive function in middle-aged and older populations, as well as whether specific areas of cognition are more affected than others. We examined the cross-sectional association between MetS and six areas of cognitive function in healthy cognitively intact adults without diabetes (n = 853, mean age 61 years) randomized in two intervention trials.
The National Cholesterol Education Program (NCEP) criteria were used to identify subjects with MetS. Cognitive function was assessed with a neuropsychological battery. A principal components analysis was used to extract five uncorrelated factors interpreted to represent five areas of cognition, and a measure of global cognition was calculated.
MetS was weakly but non-significantly associated with lower verbal learning (β=−.14 [SE(β) = 0.09], p = .15). As the number of MetS criteria increased, scores on global cognition (p trend = .01), verbal learning (p trend = .06) and semantic memory (p trend = .04) decreased. Hypertension was the only MetS risk factor that was independently correlated with lower verbal learning (β = −.17 [SE(β) = 0.08], p = .04), semantic memory (β = −.26 [SE(β) = 0.08], p = .001) and global cognition (β = −.15 [SE(β) = 0.07], p = .04).
This study adds to the evidence of an association between MetS and lower cognitive function among healthy middle-aged and older adults without CVD and diabetes, as well as confirms the correlation between hypertension and lower cognition.
PMCID: PMC2742696  PMID: 18608045
Metabolic syndrome; Cognitive function; Hypertension; Memory; Verbal learning; Global cognition
20.  Mildly Elevated TSH and Cognition in Middle-Aged and Older Adults 
It is accepted that markedly elevated thyroid-stimulating hormone (TSH) levels are associated with impaired cognitive function. However, the findings regarding the association between mildly elevated TSH levels and cognition are equivocal. The objective of this study was to assess the relation between TSH levels in the normal to mildly elevated range (0.3–10.0 mIU/L) and several domains of cognitive function.
A healthy, community-based sample of 489 men and women (40–88 years old, mean=60.5 years) enrolled in the B-Vitamin Atherosclerosis Intervention Trial were studied. A neuropsychological test battery was used to assess a broad array of cognitive functions. Four uncorrelated neuropsychological factors were extracted by principal component analysis. Using multivariable linear regression, performance on each factor was examined in relation to TSH levels, controlling for age, gender, race-ethnicity, education, homocysteine levels, low-density lipoprotein cholesterol levels, and smoking status.
TSH levels were not associated with any of the four factor scores in the total sample or in younger (age<60) or older (age≥60) subjects, although there was a trend for older subjects with higher levels of TSH to do more poorly on paragraph recall ( p = 0.06). Gender-stratified analyses showed that TSH was positively associated with scores on word list learning for females only ( p=0.003).
In this community-based sample of middle-aged to older individuals, increasing TSH levels were not associated with significantly reduced cognitive performance in any domain. Further exploration of the effects of gender on the association between TSH and cognition is warranted.
PMCID: PMC2715222  PMID: 19191743
21.  Childhood Air Pollutant Exposure and Carotid Artery Intima-Media Thickness in Young Adults 
Circulation  2012;126(13):1614-1620.
Exposure to ambient air pollutants increases risk for cardiovascular health outcomes in adults. The contribution of childhood air pollutant exposure to cardiovascular health has not been thoroughly evaluated.
Methods and results
The Testing Responses on Youth study consists of 861 college students recruited from the University of Southern California in 2007–2009. Participants attended one study visit during which blood pressure, heart rate and carotid artery intima-media thickness (CIMT) were assessed. Self-administered questionnaires collected information about health and socio-demographic characteristics and a 12-hr fasting blood sample was drawn for lipid and biomarker analyses. Residential addresses were geocoded and used to assign cumulative air pollutant exposure estimates based on data derived from the U.S. Environmental Protection Agency’s Air Quality System (AQS) database. The associations between CIMT and air pollutants were assessed using linear regression analysis. Mean CIMT was 603 μm (± 54 SD). A 2 standard deviation (SD) increase in childhood (aged 0–5 years) or elementary school (aged 6–12) O3 exposure was associated with a 7.8 μm (95% CI −0.3, 15.9) or 10.1 μm (95% CI 1.8, 18.5) higher CIMT, respectively. Lifetime exposure to O3 showed similar but non-significant associations. No associations were observed for PM2.5, PM10 or NO2 although adjustment for these pollutants strengthened the childhood O3 associations.
Childhood exposure to O3 may be a novel risk factor for CIMT in a healthy population of college students. Regulation of air pollutants and efforts that focus on limiting childhood exposures continue to be important public health goals.
PMCID: PMC3474843  PMID: 22896588
atherosclerosis; cardiovascular diseases; carotid arteries; epidemiology; pediatrics
22.  Interleukin 10 Responses Are Associated With Sustained CD4 T-Cell Counts in Treated HIV Infection 
The Journal of Infectious Diseases  2012;206(5):780-789.
Background.Inflammation persists in treated human immunodeficiency virus (HIV) infection and may contribute to an increased risk for non–AIDS-related pathologies. We investigated the correlation of cytokine responses with changes in CD4 T-cell levels and coinfection with hepatitis C virus (HCV) during highly active antiretroviral treatment (HAART).
Methods.A total of 383 participants in the Women's Interagency HIV Study (212 with HIV monoinfection, 56 with HCV monoinfection, and 115 with HIV/HCV coinfection) were studied. HIV-infected women had <1000 HIV RNA copies/mL, 99.7% had >200 CD4 T cells/μL; 98% were receiving HAART at baseline. Changes in CD4 T-cell count between baseline and 2–4 years later were calculated. Peripheral blood mononuclear cells (PBMCs) obtained at baseline were used to measure interleukin 1β (IL-1β), interleukin 6 (IL-6), interleukin 10 (IL-10), interleukin 12 (IL-12), and tumor necrosis factor α (TNF-α) responses to Toll-like receptor (TLR) 3 and TLR4 stimulation.
Results.Undetectable HIV RNA (<80 copies/mL) at baseline and secretion of IL-10 by PBMCs were positively associated with gains in CD4 T-cell counts at follow-up. Inflammatory cytokines (IL-1β, IL-6, IL-12, and TNF-α) were also produced in TLR-stimulated cultures, but only IL-10 was significantly associated with sustained increases in CD4 T-cell levels. This association was significant only in women with HIV monoinfection, indicating that HCV coinfection is an important factor limiting gains in CD4 T-cell counts, possibly by contributing to unbalanced persistent inflammation.
Conclusions.Secreted IL-10 from PBMCs may balance the inflammatory environment of HIV, resulting in CD4 T-cell stability.
PMCID: PMC3491747  PMID: 22693231
23.  Associations between White Matter Hyperintensities and β Amyloid on Integrity of Projection, Association, and Limbic Fiber Tracts Measured with Diffusion Tensor MRI 
PLoS ONE  2013;8(6):e65175.
The goal of this study was to assess the relationship between Aβ deposition and white matter pathology (i.e., white matter hyperintensities, WMH) on microstructural integrity of the white matter. Fifty-seven participants (mean age: 78±7 years) from an ongoing multi-site research program who spanned the spectrum of normal to mild cognitive impairment (Clinical dementia rating 0–0.5) and low to high risk factors for arteriosclerosis and WMH pathology (defined as WMH volume >0.5% total intracranial volume) were assessed with positron emission tomography (PET) with Pittsburg compound B (PiB) and magnetic resonance and diffusion tensor imaging (DTI). Multivariate analysis of covariance were used to investigate the relationship between Aβ deposition and WMH pathology on fractional anisotropy (FA) from 9 tracts of interest (i.e., corona radiata, internal capsule, cingulum, parahippocampal white matter, corpus callosum, superior longitudinal, superior and inferior front-occipital fasciculi, and fornix). WMH pathology was associated with reduced FA in projection (i.e., internal capsule and corona radiate) and association (i.e., superior longitudinal, superior and inferior fronto-occipital fasciculi) fiber tracts. Aβ deposition (i.e., PiB positivity) was associated with reduced FA in the fornix and splenium of the corpus callosum. There were interactions between PiB and WMH pathology in the internal capsule and parahippocampal white matter, where Aβ deposition reduced FA more among subjects with WMH pathology than those without. However, accounting for apoE ε4 genotype rendered these interactions insignificant. Although this finding suggests that apoE4 may increase amyloid deposition, both in the parenchyma (resulting in PiB positivity) and in blood vessels (resulting in amyloid angiopathy and WMH pathology), and that these two factors together may be associated with compromised white matter microstructural integrity in multiple brain regions, additional studies with a longitudinal design will be necessary to resolve this issue.
PMCID: PMC3675157  PMID: 23762308
24.  Common genetic variants in the CLDN2 and PRSS1-PRSS2 loci alter risk for alcohol-related and sporadic pancreatitis 
Whitcomb, David C. | LaRusch, Jessica | Krasinskas, Alyssa M. | Klei, Lambertus | Smith, Jill P. | Brand, Randall E. | Neoptolemos, John P. | Lerch, Markus M. | Tector, Matt | Sandhu, Bimaljit S. | Guda, Nalini M. | Orlichenko, Lidiya | Alkaade, Samer | Amann, Stephen T. | Anderson, Michelle A. | Baillie, John | Banks, Peter A. | Conwell, Darwin | Coté, Gregory A. | Cotton, Peter B. | DiSario, James | Farrer, Lindsay A. | Forsmark, Chris E. | Johnstone, Marianne | Gardner, Timothy B. | Gelrud, Andres | Greenhalf, William | Haines, Jonathan L. | Hartman, Douglas J. | Hawes, Robert A. | Lawrence, Christopher | Lewis, Michele | Mayerle, Julia | Mayeux, Richard | Melhem, Nadine M. | Money, Mary E. | Muniraj, Thiruvengadam | Papachristou, Georgios I. | Pericak-Vance, Margaret A. | Romagnuolo, Joseph | Schellenberg, Gerard D. | Sherman, Stuart | Simon, Peter | Singh, Vijay K. | Slivka, Adam | Stolz, Donna | Sutton, Robert | Weiss, Frank Ulrich | Wilcox, C. Mel | Zarnescu, Narcis Octavian | Wisniewski, Stephen R. | O'Connell, Michael R. | Kienholz, Michelle L. | Roeder, Kathryn | Barmada, M. Michael | Yadav, Dhiraj | Devlin, Bernie | Albert, Marilyn S. | Albin, Roger L. | Apostolova, Liana G. | Arnold, Steven E. | Baldwin, Clinton T. | Barber, Robert | Barnes, Lisa L. | Beach, Thomas G. | Beecham, Gary W. | Beekly, Duane | Bennett, David A. | Bigio, Eileen H. | Bird, Thomas D. | Blacker, Deborah | Boxer, Adam | Burke, James R. | Buxbaum, Joseph D. | Cairns, Nigel J. | Cantwell, Laura B. | Cao, Chuanhai | Carney, Regina M. | Carroll, Steven L. | Chui, Helena C. | Clark, David G. | Cribbs, David H. | Crocco, Elizabeth A. | Cruchaga, Carlos | DeCarli, Charles | Demirci, F. Yesim | Dick, Malcolm | Dickson, Dennis W. | Duara, Ranjan | Ertekin-Taner, Nilufer | Faber, Kelley M. | Fallon, Kenneth B. | Farlow, Martin R. | Ferris, Steven | Foroud, Tatiana M. | Frosch, Matthew P. | Galasko, Douglas R. | Ganguli, Mary | Gearing, Marla | Geschwind, Daniel H. | Ghetti, Bernardino | Gilbert, John R. | Gilman, Sid | Glass, Jonathan D. | Goate, Alison M. | Graff-Radford, Neill R. | Green, Robert C. | Growdon, John H. | Hakonarson, Hakon | Hamilton-Nelson, Kara L. | Hamilton, Ronald L. | Harrell, Lindy E. | Head, Elizabeth | Honig, Lawrence S. | Hulette, Christine M. | Hyman, Bradley T. | Jicha, Gregory A. | Jin, Lee-Way | Jun, Gyungah | Kamboh, M. Ilyas | Karydas, Anna | Kaye, Jeffrey A. | Kim, Ronald | Koo, Edward H. | Kowall, Neil W. | Kramer, Joel H. | Kramer, Patricia | Kukull, Walter A. | LaFerla, Frank M. | Lah, James J. | Leverenz, James B. | Levey, Allan I. | Li, Ge | Lin, Chiao-Feng | Lieberman, Andrew P. | Lopez, Oscar L. | Lunetta, Kathryn L. | Lyketsos, Constantine G. | Mack, Wendy J. | Marson, Daniel C. | Martin, Eden R. | Martiniuk, Frank | Mash, Deborah C. | Masliah, Eliezer | McKee, Ann C. | Mesulam, Marsel | Miller, Bruce L. | Miller, Carol A. | Miller, Joshua W. | Montine, Thomas J. | Morris, John C. | Murrell, Jill R. | Naj, Adam C. | Olichney, John M. | Parisi, Joseph E. | Peskind, Elaine | Petersen, Ronald C. | Pierce, Aimee | Poon, Wayne W. | Potter, Huntington | Quinn, Joseph F. | Raj, Ashok | Raskind, Murray | Reiman, Eric M. | Reisberg, Barry | Reitz, Christiane | Ringman, John M. | Roberson, Erik D. | Rosen, Howard J. | Rosenberg, Roger N. | Sano, Mary | Saykin, Andrew J. | Schneider, Julie A. | Schneider, Lon S. | Seeley, William W. | Smith, Amanda G. | Sonnen, Joshua A. | Spina, Salvatore | Stern, Robert A. | Tanzi, Rudolph E. | Trojanowski, John Q. | Troncoso, Juan C. | Tsuang, Debby W. | Valladares, Otto | Van Deerlin, Vivianna M. | Van Eldik, Linda J. | Vardarajan, Badri N. | Vinters, Harry V. | Vonsattel, Jean Paul | Wang, Li-San | Weintraub, Sandra | Welsh-Bohmer, Kathleen A. | Williamson, Jennifer | Woltjer, Randall L. | Wright, Clinton B. | Younkin, Steven G. | Yu, Chang-En | Yu, Lei
Nature genetics  2012;44(12):1349-1354.
Pancreatitis is a complex, progressively destructive inflammatory disorder. Alcohol was long thought to be the primary causative agent, but genetic contributions have been of interest since the discovery that rare PRSS1, CFTR, and SPINK1 variants were associated with pancreatitis risk. We now report two significant genome-wide associations identified and replicated at PRSS1-PRSS2 (1×10-12) and x-linked CLDN2 (p < 1×10-21) through a two-stage genome-wide study (Stage 1, 676 cases and 4507 controls; Stage 2, 910 cases and 4170 controls). The PRSS1 variant affects susceptibility by altering expression of the primary trypsinogen gene. The CLDN2 risk allele is associated with atypical localization of claudin-2 in pancreatic acinar cells. The homozygous (or hemizygous male) CLDN2 genotype confers the greatest risk, and its alleles interact with alcohol consumption to amplify risk. These results could partially explain the high frequency of alcohol-related pancreatitis in men – male hemizygous frequency is 0.26, female homozygote is 0.07.
PMCID: PMC3510344  PMID: 23143602
25.  Insulin Resistance and Cognition Among HIV-Infected and HIV-Uninfected Adult Women: The Women's Interagency HIV Study 
Cognitive impairment remains prevalent in the era of combination antiretroviral therapy (cART) and may be partially due to comorbidities. We postulated that insulin resistance (IR) is negatively associated with cognitive performance. We completed a cross-sectional analysis among 1547 (1201 HIV+) women enrolled in the Women's Interagency HIV Study (WIHS). We evaluated the association of IR with cognitive measures among all WIHS women with concurrent fasting bloods and cognitive testing [Trails A, Trails B, and Symbol Digit Modalities Test (SDMT)] using multiple linear regression models. A smaller subgroup also completed the Stroop test (n=1036). IR was estimated using the Homeostasis Model Assessment (HOMA). Higher HOMA was associated with poorer performance on the SDMT, Stroop Color-Naming (SCN) trial, and Stroop interference trial, but remained statistically significant only for the SCN in models adjusting for important factors [β=3.78 s (95% CI: 0.48–7.08), p=0.025, for highest vs. lowest quartile of HOMA]. HIV status did not appear to substantially impact the relationship of HOMA with SCN. There was a small but statistically significant association of HOMA and reduced neuropsychological performance on the SCN test in this cohort of women.
PMCID: PMC3332367  PMID: 21878059

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